A KLI DROPPED ONTO PILLOWS [Nezirim: Gerama]
Gemara
26b (Rabah): If Reuven threw Levi's Kli off the roof, and there were pillows on the ground, and David removed them, or even if Reuven removed them, he is exempt.
Question: What is the reason?
Answer: When he threw it, his arrows ceased (it was not destined to break).
98b (Rabah): If Reuven burned Shimon's loan document, he is exempt. He can say 'I burned a mere piece of paper!'
(Ameimar): The opinion that obligates for Garmi (direct causation) obligates paying the full value of the document. The opinion that exempts for Garmi obligates paying the value of the paper.
A case occurred, and Rafram forced Rav Ashi to pay the full value.
Rishonim
Rif: Presumably, the Halachah does not follow Rabah, who exempts for Garmi. He holds that one who burned another's document is liable only b'Yedei Shamayim. The Halachah does not follow him. Ameimar forced Rav Ashi to pay fully.
Nimukei Yosef (11b DH Mifsekei): The Meforshim agree with the Rif that the Halachah does not follow Rabah. We obligate for Garmi. Since it will surely be damaged, pulling away the pillows is Garmi, not Gerama.
Rosh (2:16): The Ri explained that this is only Gerama, since he did not do an action to the matter that was thrown. Presumably, this is correct.
Hagahos Ashri: All agree that he is exempt. Garmi is when he himself damaged another's property, or when he damages at the time he acts.
Rambam (Hilchos Chovel u'Mazik 7:7): If Levi threw his Kli off the roof, and there were pillows on the ground, and Shimon removed the pillows and the Kli broke, he pays full damage. Removing the pillows caused it to break. The same applies to all similar cases.
Rebuttal (Ra'avad): The Rambam obligates because we obligate for Garmi. Not all agree in this case, for he did not do anything to the Kli.
Rambam (8): If Reuven threw Levi's Kli off the roof, and there were pillows on the ground, and Levi removed them, Reuven is liable, for his throwing is the first cause of the breakage. If Shimon removed them, he and Reuven are liable, for both of them caused the loss to Levi.
Rebuttal (Ra'avad): I never saw such a blunder. Reuven's arrows stopped! The Rambam obligates Shimon; others exempt him, like I wrote.
Magid Mishneh: The Rambam explains that Rabah exempts the one who threw the Kli. He did not discuss the one who removed the pillows. Perhaps he agrees that he is liable! The Rif says that the Halachah does not follow Rabah, who exempts the one who threw it. The Ra'avad holds like Rashi.
Kesef Mishneh: What is the Ra'avad's question? The Rambam holds that the Halachah does not follow Rabah, like the Rif said!
Lechem Mishneh: The Kesef Mishneh's text says 'or the thrower removed the pillows.' If so, perhaps the Rif means that the Halachah is unlike Rabah who exempts for removing, but we also exempt for throwing, for his arrows ceased! This is why the Magid Mishneh says that these words were not in the Rambam's text.
Bach (CM 386:4 DH umi'Kol): The Rambam held that the Gemara did not explain why the one who removed the pillows is exempt, for it is obvious. He is the last cause of the damage. When Levi threw his own Kli, the one who removed the pillows pays full damage, for he is the first (and only) cause of damage.
Poskim
Shulchan Aruch (CM 386:3): If Levi threw his Kli off the roof, and there were pillows on the ground, and had it fell on them it would not have broken, and Shimon removed the pillows and the Kli broke, he is liable. The same applies to all similar cases.
Shiltei ha'Giborim (11b-12a, cited in Drishah 2): When Levi threw his own Kli, surely he did not intend that it break. Therefore, Shimon pays full damage. If Reuven threw Levi's Kli, then the Rambam holds that Reuven and Shimon are partners in the damage. If Reuven threw Levi's Kli, and Levi himself removed his pillows, Reuven is liable. Levi may remove his pillows whenever he wants. Reuven caused the damage; he had no right to throw the Kli. If one who does not own the pillows removed them, since he had no permission, he and Reuven are partners in the damage.
Bach (4 DH v'Nir'eh): One who throws his own Kli knows that only the owner of the pillows may remove them. Presumably, he knew that the owner was not here. (Therefore, anyone else who removed them is liable.) The owner of the pillows may remove them whenever he wants, just like David may take back his cover that Yosef used it to cover a pit. Even if Levi removed his pillows, without concern that his Kli will break, the one who threw it liable.
Rema: Some say that this is Gerama, and he is exempt.
Gra (6): This is like Tosfos, who distinguishes Gerama from Garmi, for in many places we hold that Gerama is exempt.
Shach (18): The Maharshal and many Poskim hold like this. It is the primary opinion.
Rema (ibid.): Even if Shimon threw Levi's Kli off the roof, and there were pillows on the ground, and Shimon himself removed them, he is exempt. He is exempt for throwing it, for it was not destined to break. Removing the pillows is mere Gerama.
Shach (19): He is exempt only if he pushed the Kli off the roof. If he lifted it, he acquired it like a thief, and must return it.
Gilyon Maharsha: Rashi (53a DH Nofal) similarly says that if an animal fell into David's pit due to the noise of David digging, since he is exempt for causing it to fall (it is Gerama), he is exempt also for damage due to his pit.